The Rubrics of the Missale Romanum 1962

III. The Beginning of Mass

1.
When the priest has descended to the lowest level of the Altar, he
turns toward the Altar, and standing in the middle, with his hands
joined before his breast with fingers extended and together, and with
his right thumb over his left in the form of a cross (which form is
always to be observed when joining the hands until after the
Consecration), and with his head uncovered, having first reverenced the
Crucifix or Altar, or if a Tabernacle containing the Blessed Sacrament
is on the Altar, having genuflected, standing erect, he begins the Mass.

2. If he is
about to celebrate
in the presence of the Supreme Pontiff, he stands before the lowest
level of the Altar at the Gospel side before the Pontiff, where,
genuflecting, he waits. Having received the blessing, he rises, and
standing facing the Altar, begins the Mass. If, however, he is about to
celebrate in the presence of a Cardinal, Legate of the Apostolic See,
or a Patriarch, Archbishop, or Bishop in his residence or place of
jurisdiction, he stands before the lowest level at the Gospel side, as
above, and waits; after the sign has been given, he makes a profound
reverence to the Prelate, and facing the Altar, begins the Mass.

3. If
however he is
celebrating solemnly in the presence of the Supreme Pontiff or another
of the aforementioned Prelates in churches within their jurisdiction,
he stands to the left of the Prelate, makes the Confession with him,
and does everything else as prescribed in the Roman Pontifical and
Ceremonial.

4. Standing
thus before the
lowest step of the Altar, as described above, he signs himself with his
right hand from forehead to breast with the sign of the cross, saying
in an intelligible voice:

In nomine Patris, et Filii,
et Spiritus Sancti. Amen.

After he has
said this, he
should pay no attention to any Celebrant at any other Altar, even if he
elevates the Blessed Sacrament, but continuing, he attends to his own
Mass until the end. This is to be observed even in solemn Masses, and
also by the ministers.

5. When he
crosses himself,
the Priest always holds his left hand on his breast. In other blessings
at the Altar, and in blessing the oblation or anything else, he places
it upon the Altar, unless otherwise indicated. In blessing himself, he
turns the palm of his right hand toward himself, and with all his
fingers together and extended, makes the sign of the cross from
forehead to breast, and from left shoulder to right. If, however,
another person or thing is to be blessed, the little finger is turned
toward that which (or whom) is to be blessed, and he extends his entire
hand toward that to be blessed, with his fingers together and extended,
which is to be observed in all blessings.

6. After he has said In nomine Patris, etc. as
above, he again joins his hands before his breast and pronounces in a
clear voice the Antiphon:

Introibo ad altare Dei.

The minister
kneeling behind him and to his left replies: (In Solemn Masses, the
minister stands henceforth)

Ad Deum, qui laetificat juventutem meam.

Then the
Priest, in the
same manner, begins, alternating with the minister or ministers, to say
the psalm, continuing to the end with the Gloria Patri, and bowing his
head to the Cross at the Gloria
Patri:

(The psalm is
never
omitted, except in Masses for the dead, and in Masses during the time
lasting from Passion Sunday up to Holy Thursday inclusive, during which
time however the antiphon Introibo
is said with the ministers, as described above, with the Priest adding
immediately V.Adjutorium nostrum, etc., as
below)

7. After
the Introibo
antiphon has been repeated, making the sign of the cross with his right
hand from forehead to breast, he says:

V. Adjutoriumnostrum in nomine Domini.

R.Qui
fecit coelum et terram.

Then, bowing
profoundly
before the Altar, with his hands joined, he says the Confiteor,
striking his breast thrice with his right hand at the mea culpa, with his left hand
on his breast:

8.
If he is in the presence of the Pontiff, a Cardinal, a Legate of the
Apostolic See, or a Patriarch, Archbishop, or Bishop, in their
established Province, City, or Diocese, when is otherwise said vobis, fratres, he
says, tibi, Pater;
similarly at the end where otherwise vos,
fratres is said, he says te,
Pater. When saying this he genuflects to the Supreme
Pontiff, or bows profoundly to the other Prelates.

9. The
ministers then say the
confession in the same manner. When the minister, and whoever is
present (even if it were the Supreme Pontiff) responds Confiteor, etc., he
says tibi, Pater,
and te, Pater,
turning somewhat toward the Celebrant:

And if he is a
Bishop, or Abbot, as above, he puts on the Maniple, having kissed it in
the middle. The ministers reply:

Amen.

Then, bowing
with his hands joined, he proceeds with Deus, tu conversus, and with
what follows in the Order of Mass, up to Aufer a nobis, etc., in a
clear voice:

V.Deus,
tu conversus vivificabis nos.

R.Et
plebs tua laetabitur in te.

V.Ostende
nobis, Domine, misericordiam tuam.

R.Et
salutare tuum da nobis.

V.Domine,
exaudi orationem meam.

R.Et
clamor meus ad te veniat.

V.Dominus
vobiscum.

R.Et
cum spiritu tuo.

Then,
extending and then joining his hands, he says in a clear
voice:

Oremus.

11.
And if celebrating in the presence of the Supreme Pontiff, or other
Prelates, as above, having made a genuflection to the Supreme Pontiff,
or a deep reverence to the other prelates, he goes to the middle of the
Altar below the lowest step, and there begins secretly Aufer a nobis, as in the Order
of Mass.

12.
Sometimes the psalm Judica
me, Deus with its antiphon, the confession with the
absolution, the following verses and the prayers Aufer a nobis and Oramus te, Domine
are to be omitted, according to the norm of rubric 424. In these cases
the Celebrant, having made due reverence to the Altar, ascends it
saying nothing, and having put down the Chalice, kisses the Altar,
again saying nothing. Then, unless the Altar is to be incensed, he
begins the Introit antiphon at the Epistle side, as below.